The Advanced Configuration and Power Interface (ACPI) is an open standard that allows the operating system to control the amount of power given to each device attached to the computer. This helps manage power consumption efficiently, enabling features like sleep mode and hibernation, which save energy when the computer is not in use. Introduced in 1996, ACPI provides a way for the operating system to communicate with the hardware, allowing for better resource management and improved performance. It supports various power states for devices, ensuring that they use only the necessary power, which is especially important for laptops and mobile devices.